#version 3.7;

#include "colors.inc"
#include "rad_def.inc"

global_settings {
  assumed_gamma 1
  radiosity { Rad_Settings (Radiosity_Default, off, off) }
}

camera {
  location <0, 1, -10>
  look_at 0
  angle 30
}

light_source { <250, 250, -1000> White }

plane { y, -1.5
  pigment { checker Green White }
}

#declare Foo =
  box { -1, 1 pigment { Red } }

#declare Bar =
  union {
    // There are surface coincidences _within_ this union.
    box { <-.75, -.75, -2>, <.25, .25, 0> }
    box { <-.25, -.25, -2>, <.75, .75, 0> }
    pigment { Green }
  }

// No surface of Foo is coincident with any surface of Bar.

#declare Baz =
  difference {
    object { Foo }
    object { Bar }
  }

object { Baz }